Am I stupid?

kittycarr

The metric system seriously f*cks my brain.

8oz is 8oz, correct?  Or no?

I have a Starbucks cup I use for my coffee every morning.  It's a 16oz cup.  I fill it halfway with my milk before steaming.  If I take that milk and pour it in my measuring cup, it should be at the 1cup/8oz mark.  But it's not.  It's a cup and a half measurement. 

Using the example that you are supposed to drink six 8oz glasses of water a day ~ I have a 12oz cup that I use to drink my water from.  If I used my measuring cup again and filled it to 1cup, my 12oz cup is then only 1/3 of the way full after I pour it back in.

WTF is going over my head?

joseysbride

I suppose the fact that your cup says it is 16 oz really depends on how full the manufacturer expects you to fill it.  Is it 16 oz to the very brim or 16 oz to an inch below the brim?  You don't know what they assumed.

That, and when you are saying you fill the cup half-way...is the cup tapered at all?  Because unless it is a perfect cylinder, what appears the half-way mark isn't going to be the half-way volume-wise.

Make sense?

joseysbride

And wow, that is a lot of thought put into a cup right there!

sunshiny79

Is it b/c they leave room for spillage?

littlemermaid

Is the cup tapered, that will definitely make a difference where the half way point is?  Also, they may not expect you to fill it to the top?

Bellisimo

It probably has to do with the theory of conservation (Piaget).  What shape is the cup?  Smaller at the bottom and wider towards the top?  It gives the appearance of being 1/3 full?  Children around age 7 (in the Concrete Operational Stage) will begin to realize that quantity does not change despite the shape/size of the container it is in.  If I poured equal amounts of water into two different glasses, one being tall and slender and the other being short and wide, my child would swear that the tall and slender glass contained more water. 

kittycarr

It is but not much and the biggest part of the cup is the top.